An implantable penile prosthetic includes a pump attachable between a body implantable reservoir and a cylinder that is implantable into a corpora cavernosum of a penis. The body implantable reservoir is substantially empty of liquid prior to implantation and includes a first end portion including a neck having an opening that is adapted to communicate with the pump and an end wall on an end of the reservoir that is opposite of the neck. The end wall extends between a first surface of the reservoir and a second surface of the reservoir. The reservoir includes a first substantially planar edge surrounding a periphery of the first surface of the reservoir and a second substantially planar edge surrounding a periphery of the second surface of the reservoir. The first surface is concave relative to the first edge and the second surface is concave relative to the second edge.